Hydraulic system



March 12, 1940. w; H P R 2,193,497

HYDRAULIC SYSTEM Original Filed March 19, 1936 2 Sheets-Sheet 1 l 1 f l 5 -25 E3 ll!!!" 64 54 i 3 25 llwitw l WILLIAM H. SPIRE, DECD.

A RENE D. SPIRLADMTRIX,

March 12, 1940. w sp 2,193,497

HYDRAULIC SYSTEM 7 Original Filed March 19, 1936 2 Sheets-Sheet 2 D VEEEF WILLIAM H. 5P|RE,DECD. IRENE D. SPIRE, Anm'rmx.

Patented Mar. 12, 1940 UNITED STATES PATENT", OFFICE,

2,193,497 HYDRAULIC SYSTEM William H. Spire, deceased, late of Cleveland,

Ohio, by Irene D. Spire, administratrix, Cleveland, Uhio, assignor to Thompson, Products,

Incorporated, of Ohio Cleveland, Ohio, a corporation Original application March 19, 1936, Serial No. 1 69,745, nowPatent No. 2,162,133, dated June 13, 1939. Divided and'this applicationJanuary 23, 1937, Serial No. 121,972

I 2 Claims. (Cl. 121--38) No. 2,037,604, and is a division of application.

Serial No. 69,745, filed on March 19, 1936, now Patent No. 2,162,133, and entitled Hydraulic force multiplying machine.

This invention relates particularly to a-hydraulic drive for a clamp or the like.

It is one of the objects of the presentinvention to provide an improved hydraulic system in which a hydraulic circuit controls movement of a pair of connected pistons employed as the operator of a movable work holding or moving element.

It is an important object of the present invention to provide a hydraulic system operatively connected with a reciprocable work element so that reciprocation of the work element is made possible without the manipulation of four-way valves or the like, and without necessitating the use of such valves.

It is a further important object of the present invention to provide a hydraulic. system operatively connected with a reciprocable work element so that reciprocation of the work element may be obtained by the reversal of the direction of rotation of a simple pump.

It is an important object of the present inven tion to provide a hydraulic syste n operatively connected with a reciprocable work element through means whereby the simple manipulation of a switch produces reciprocation of the work element.

It is a further important object of the present invention to provide a hydraulic system having a single fluid connection with each of a pair of longitudinally aligned cylinders for reciprocation of a piston in each of said cylinders, respectively, and the reciprocation or a work element connected to both of the pistons.

Other and further objects of this invention will appear hereinafter from the. disclosure in the drawings and specification.

The invention, in a preferred form, is illustrated in the drawings and hereinafter more fully described.

In the drawings:

Figure l is a side elevational view of clamp operator with parts in plan, parts in section, and parts broken.

Figure 2 is a front elevational View of the operator, with parts in plan, parts in section, and parts broken. I

Figure 3 is a diagrammatic showing of a hydraulic system of which the operator of Figure 1 is a component.

Figure 4 is a detail view of an air venting device in the hydraulic system, with parts in plan and parts in section. In Figure 1 there is shown a hydraulic clampactuating device indicated generally by the nuinerals It. While this device is describedas means for actuating the jaws of a clamp in the application which became Patent No. 2,037,604 of April 14, 1936, in connection with the operation of a metal gathering machine, it will be obvious that it is capable of use in other, use associations. e 1

i In the patent just referred to, the device appears as' the operator of a clamp in which the jaws are capable ofbeing widelyseparated to permit the ready insertion or removal of the thing clamped, and the opening and closing of the jaws of the clampare quickly effected by a simple manipulation of a switch. The clamp is one terminal of an electric circuit of which the other is an 'anvil'towards whicha rod is pushed through the'clamp, and it is essential that firm contact be made'with the clamped rod to avoid excessive heating of the clamp. Imperfect contact would-result in excessive power loss in the clamp Where it contacts therod, arcing, and a.

possible change in the material of the rod while subjected to an undesired heat and mechanical treatment,

The device also appears as a hydraulic operator to produce relative'movement of the jaws of a clamp and arranged to apply great pressure during a very small part of the total pressure-applying stroke, and at theend of the stroke.

A clamp H is connected to the clamp-actuating device it, and the'clamp comprises a stationary lower jaw 52' and a hinged upper jaw I3, both of which are suitably mounted on a frame 14.

The clamp II is adapted to clamp a rod or an article, indicated generally by the numerals l5,

between the jaws thereof, and the jaws are pro and 2sopaced components terminating in a curved toe A pair of rollers 2| and 22 slide guided between the opposed faces of the rail l9, and the rollers are held for rotation in assembled relation by a pair of connecting side links 23.

The rollers are adapted to be pushed downwardly by a piston 24 in a bore 25 of a cylindrical structure 26 by a link or yoke 21 connecting the piston with the rollers, and they are adapted to be moved upwardly by a piston 28 in an upper bore 29 of the cylindrical structure 26 through side links 30 pivotally connected to the upper piston and to the lower piston.

There is a solid portion 3| between the upper and lower bores of the structure 26, and this solid portion is provided with passages 32 and 33 communicating with the lower and upper bores, respectively, and connected to pipes 34 and 35, respectively, which are threaded in the solid portion.

The pipes 34 and 35 are connected to a conventional gear type of pump 36, and in the operation of the hydraulic system, as described hereinafter, each of the pipes becomes alternately a suction and a discharge line of the pump.

As shown in Figure 3, a pipe loop 37 is connected to the pipes 34 and 35, and a pipe 38 connects the loop with an open oil reservoir 39. A pair of conventional check valves 48 and 4| are interposed in the pipe loop, one on each side of its connection to the pipe 38, to prevent flow of oil from the pipes 34 and 35 towards the reservoir.

A relief pipe 42 is connected to the pipes 34 and 35 to discharge oil to the reservoir, and in its connection with these pipes there are interposed conventional check valves 43 and 44 to prevent the passing of the discharge of the pump 36 from the discharge line to the suction line. In the relief pipe there is interposed a weighted relief ,valve 45 of conventional form.

The suction side of the pump is always in communication with the open reservoir 39 to replenish the pressure part of the system in the event of loss of oil through leakage.

The pump 36 may be driven by a 3-phase induction motor 46 connected to power lines 41 through a conventional form of reversing switch 48, or by other reversible power means.

When the pump 36 is rotated in one direction it sucks oil through the pipe 35 and discharges oil through the pipe 34, so that the piston 24 is pushed down and the piston 28 is pulled down.

Reversal of the direction of rotation of the pump by simply moving the switch 48 to the reversed position eiiects movement of the pistons 24 and 28 in the opposite direction by now reversing the flow of oil, the pipe 34 becoming a suction line and the pipe 35 becoming the pressure line.

The pistons may be said to be each alternately suction and pressure operated.

A pair of links 49 are pivotally connected at their upper end to the lower end of the link 23, as at 58, and are also pivotally connected at their lower end, as at 5|, to the end of the lever or clamp jaw l3 at a point above and remote from where the jaw is hinged to the frame l4, as at 52.

It will now be obvious that reciprocation of the jaw I3 is effected by the manipulation of the reversing switch 48.

The diameter of each of the pistons 24 and 28 is relatively small and their displacement relatively small in comparison with the volumetric capacity of the pump so that it requires but a few revolutions of the pump to make the pistons traverse their full stroke, and the opening and closing of the jaws of the clamp is quickly effected in response to manipulation of the reversing switch 48. In a working installation the pump is driven by a H. P. motor at a speed of 1750 R. P. M. and is capable of handling about one-third of a gallon of oil per minute against a pressure of 300 lbs. per square inch. The inertia of a motor of this size is low and it may be quickly reversed, and the system lends itself to use where reciprocation of the pistons, and

their connected work element, at a high reversal frequency is desired.

Means are provided to release air or gases that find entrance to the cylinders 25 and-29 and tend to cushion the pistons 24 and 28, and such means comprise air-venting devices, indicated generally by the numerals 53, which are connected in the pipe lines 34 and 35, respectively, to vent air and oil by vent pipes 54 to the open oil reservoir 39.

The air-venting devices 53 each comprise a T- fitting 55 into which a plug body 56 is threaded at the upper end of the T. The plug body is provided with a small metering bore 51 opening into the T and forming an extension of an enlarged bore 58 in the plug body. A ball 59 in the plug body normally closes the bore 51 under the pressureof a spring 68 which is compressed by the entering of a threaded plug 6| in the plug body. A gasket 62 is placed between the head of the plug 6| and the plug body to make an oil tight seal. The plug body 56 is also provided with a side bore 63 in communication with the bore 58 and with the vent pipe 54.

When one or the other of the pipes 34 and 35 is carrying oil under pressure some of this oil will be forced through the bore 51 and return to the reservoir, 39 by the vent pipe 54. If air is present in the feed pipe it will naturally find its way to the top ofthe T-fitting and be vented with the oil passing out to the vent pipe 54.

When the pipes 34 or 35 are suction lines it will be obvious that the spring 68 will force the ball 59 to close the bore 51, and that there is no suction on the vent pipe 54.

The oil passing through the metering bore 51 is insignificant in volume compared with that being pumped through the feed lines 34 and 35, and since the pump 36 is in communication with the open reservoir 39 there is no possibility of depleting the system.

The vent devices 56 are eminently simple in construction, and are preferred to traps in an installation of the kind described.

It will be understood that many changes may be made and numerous details of construction may be varied through a wide range without departing from the principles of the invention.

What is claimed is:

1. A hydraulic machine comprising a vertical support, a vertically extending and unitary cylinder structure secured at its lower end to the upper end of said support, said cylinder structure consisting of an elongated cylinder block having a pair of oppositely directed longitudinal bores to define a pair of cylinders in back-to-back relation and with each cylinder having an open end, each of said pair of cylinders being provided with a piston therein, respectively, said pistons being normally reciprocable through the open ends of said cylinders, rigid link means pivotall; connected to said pistons to compel synchronized movement of said pistons, a work element pivotally connected to one of said pistons, and fluid reversing means in fluid connection with each of said cylinders arranged to cause reciprocation of said pistons. Y

2. A hydraulic machine comprising a vertical support, a vertically extending and unitary cylinder structure secured at its lower end to 'the upper end of said support, said cylinder structure consisting of an elongated cylin der block having a pair of oppositely directed longitudinal bores to define a pair of cylinders in back-to-back relation and with each cylinder having an open end, each of said pair ofcylinders being provided with a piston therein, respe ctively, said pistons being normally reciprocaole through the open ends of said cylinders, rigid link means pivotally connected to said pistons to compel synchronized movement of said pistons, a roller mounted for rotation on one of said'pistons, means defining a guideway for guided movement of said roller, a work element pivotally connected to one of said pistons, and fluidreversing means in fluid connection with each of said cylinders arranged to cause reciprocation of said pistons I IRENE D. SPIRE, Administratrim of the Estate of William H. Spire,

Deceased. 

